Absorbable iron-based alloy medical instrument implant and manufacturing method

Abstract

Absorbable iron-based alloy implanted medical device and manufacturing method thereof. The iron-based alloy implanted medical device comprises an iron-based alloy substrate (11), a degradable polymer layer (13) disposed on a surface of the iron-based alloy substrate (11), and a tannic acid chemical conversion film (12) disposed on a surface of the iron-based alloy substrate (11). After the medical device is implanted into a body, the tannic acid chemical conversion film (12) is configured to protect the iron-based alloy substrate (11) coated thereby from being in contact with a body fluid, thereby ensuring that the device meets a clinical mechanical property requirement in the early stage of implantation. Furthermore, the iron-based alloy implanted medical device has a decreased size, and produces a decreased amount of a corrosive product after being implanted, facilitating faster absorption or elimination of the corrosive product.

The invention claimed is: 
     
       1. An absorbable iron-based alloy implanted medical device, comprising:
 an iron-based alloy substrate; 
 a tannic acid chemical conversion film disposed on the surface of the iron-based alloy substrate, with the tannic acid chemical conversion film having a thickness of 0.4 to 0.5 um and covering 95 percent of the surface of the iron-based substrate; and 
 a polylactic acid coating with a thickness of 6 um completely covering the tannic acid chemical conversion film. 
 
     
     
       2. The absorbable iron-based alloy implanted medical device according to  claim 1 , wherein the iron-based alloy substrate is an iron-based alloy or pure iron with a carbon content less than or equal to 2.11 weight percent. 
     
     
       3. The absorbable iron-based alloy implanted medical device according to  claim 1 , wherein the tannic acid chemical conversion film is a product generated by reaction of tannic acid and the iron-based alloy substrate. 
     
     
       4. The absorbable iron-based alloy implanted medical device according to  claim 1 , wherein the polylactic acid coating comprises an active drug which is an anti-intimal hyperplasia drug for treating vascular restenosis, an anticoagulant, an anti-platelet adhesion drug, an anti-infective drug, an antibacterial drug or an anti-tumor drug. 
     
     
       5. The absorbable iron-based alloy implanted medical device according to  claim 1 , wherein the implanted medical device is a heart implant, a blood vessel implant, a gynecological implant, an andrological implant, a respiratory implant or an orthopedic implant. 
     
     
       6. An absorbable iron-based alloy implanted medical device, comprising:
 an iron-based alloy substrate; 
 a tannic acid chemical conversion film disposed on the surface of the iron-based alloy substrate, with the tannic acid chemical conversion film having a thickness of 0.8 to 1.0 um and completely covering the surface of the iron-based substrate; and 
 a polylactic acid coating with a thickness of 8 um partially covering the tannic acid chemical conversion film. 
 
     
     
       7. The absorbable iron-based alloy implanted medical device according to  claim 6 , wherein the iron-based alloy substrate is an iron-based alloy or pure iron with a carbon content less than or equal to 2.11 weight percent. 
     
     
       8. The absorbable iron-based alloy implanted medical device according to  claim 6 , wherein the tannic acid chemical conversion film is a product generated by reaction of tannic acid and the iron-based alloy substrate. 
     
     
       9. The absorbable iron-based alloy implanted medical device according to  claim 6 , wherein the polylactic acid coating comprises an active drug which is an anti-intimal hyperplasia drug for treating vascular restenosis, an anticoagulant, an anti-platelet adhesion drug, an anti-infective drug, an antibacterial drug or an anti-tumor drug. 
     
     
       10. The absorbable iron-based alloy implanted medical device according to  claim 6 , wherein the implanted medical device is a heart implant, a blood vessel implant, a gynecological implant, an andrological implant, a respiratory implant or an orthopedic implant. 
     
     
       11. An absorbable iron-based alloy implanted medical device, comprising:
 an iron-based alloy substrate; 
 a tannic acid chemical conversion film disposed on the surface of the iron-based alloy substrate, with the tannic acid chemical conversion film having a thickness of 1.6 to 1.8 um and completely covering the surface of the iron-based substrate; and 
 a polylactic acid coating with a thickness of 12 um completely covering the tannic acid chemical conversion film. 
 
     
     
       12. The absorbable iron-based alloy implanted medical device according to  claim 11 , wherein the iron-based alloy substrate is an iron-based alloy or pure iron with a carbon content less than or equal to 2.11 weight percent. 
     
     
       13. The absorbable iron-based alloy implanted medical device according to  claim 11 , wherein the tannic acid chemical conversion film is a product generated by reaction of tannic acid and the iron-based alloy substrate. 
     
     
       14. The absorbable iron-based alloy implanted medical device according to  claim 11 , wherein the polylactic acid coating comprises an active drug which is an anti-intimal hyperplasia drug for treating vascular restenosis, an anticoagulant, an anti-platelet adhesion drug, an anti-infective drug, an antibacterial drug or an anti-tumor drug. 
     
     
       15. The absorbable iron-based alloy implanted medical device according to  claim 11 , wherein the implanted medical device is a heart implant, a blood vessel implant, a gynecological implant, an andrological implant, a respiratory implant or an orthopedic implant.